Experts have urged caution in interpreting a decline in foodborne illness figures in the United Kingdom and Ireland during the coronavirus outbreak as an actual drop in infections.

Public Health England (PHE) said it is not yet possible to know the impact of the COVID-19 pandemic on testing of gastrointestinal pathogens and reporting of results to the agency.

Data on laboratory reports of gastrointestinal infections in England and Wales reported to PHE from the end of February to end of March shows Campylobacter was down from 930 in February to 394 in March. Salmonella declined from 93 reports to 67 and norovirus from 204 to 38, respectively.

More of the iceberg underwater
Professor Alan Reilly, from the Institute of Food and Health at University College Dublin, used the example of an iceberg to explain the current situation on reports of foodborne infections.

“We talk about the tip of the iceberg when it comes to foodborne illness, I think there is probably more of the iceberg underwater now than on top during these pandemic times. The individual, milder cases won’t be reported. That’s just how things are but the more serious ones should still be caught,” he told Food Safety News.

“We’ll need to look back at a longer period than three months when we have more data to analyze and assess. Just now it is difficult to say exactly what is happening. That study will be done at the end of the year as people are evaluating surveillance monitoring data for 2020 and it will be compared with other years, the same way we are looking at fatalities and the increase in deaths.”

Other PHE data shows reports of food poisoning in England and Wales are at 1,700 since the start of 2020 to May. That’s compared to 2,674 and 3,071 in the same period in 2019 and 2018 respectively.

When asked if there were less people getting food poisoning or a decline in reporting, Public Analyst Dr. Duncan Campbell, said it was probably a bit of both.

“There will be much less food that is prepared outside of the home being consumed, certainly no all-you-can-eat buffets or mass catering events. It is likely that those offering deliveries have streamlined their menus, so there will be less food stored. People are washing their hands more. Equally people who think that they have food poisoning are much less likely to report it or seek medical help.”

One expert, who did not wish to be named, told Food Safety News that there are multiple factors to consider:

“With restaurants closed the opportunities for food poisoning are reduced, and I don’t expect home delivered food is on anything like the scale ‘eat-in’ was when we could do it. In addition, the statistics depend on GP notifications with or without a stool sample. GP’s are doing most consultations by phone or video link and there seems to be a general reluctance to attend. So, food poisoning in individual households will be unreported for a variety of reasons.”

PHE suspends some services
In April, the World Health Organization and Food and Agriculture Organization issued guidance for authorities responsible for national food safety control systems.

The document covers food fraud, testing and analysis in labs and national food safety inspection programs.

“A minimum capacity in microbiological and chemical safety needs to be maintained to support food inspections of high risk businesses, for dealing with consumer complaints and food incidents, and for the investigation and management of outbreaks of foodborne illness. Public health disease surveillance systems may have a reduced capacity to identify human cases of foodborne illness but it is essential that a minimum national capability is maintained,” according to the guidance.

“Some monitoring and surveillance programs that are routinely carried out by competent authorities could be temporarily suspended during this pandemic without jeopardizing the safety of foods, the health of the consumer, or international trade. Temporarily suspending low-risk control activities will allow authorities to continue to safeguard the health and safety of their staff while refocusing efforts in areas of higher risk and towards activities that are critical to the safety of food.”

At PHE’s gastrointestinal bacteria reference unit, identification and typing of pathogens including Bacillus, Clostridium perfringens, Campylobacter, Vibrio and Yersinia have been temporarily suspended, but could restart if there is an outbreak.

Continuing services are detection of Shiga toxin-producing E. coli (STEC) from stool specimens and isolates using PCR, detection of Clostridium botulinum and botulinum toxin from food, stool, serum and tissue samples, and confirmation of identity and typing of Salmonella, Shigella, STEC and Listeria using whole genome sequencing.

The expert said refocusing with some typing and identification services suspended may be good resource management:

“It should be on a risk basis, with lower risks that don’t directly impact on food safety being suspended in favor of COVID-19 testing, monitoring and tracking. Whether or not this means we could miss outbreaks – only time will tell but it’s essential that food safety is maintained especially in novel supply chain situations.”

Irish outlook
The decline of foodborne illness records is also taking place in Ireland. Based on Health Protection Surveillance Centre (HPSC) data, from the start of the year until early May, Campylobacter reports are down from 921 in the same period in 2019 to 592 this year. There has also been a smaller fall in Salmonella and E. coli infections.

Reilly, former chief executive of the Food Safety Authority of Ireland, said mitigating factors are playing a part in the figures.

“It is not surprising that a reduced number of cases of foodborne diseases are being reported as the public health specialists who would normally be tracking and investigating cases and outbreaks are focusing their major efforts and attention on COVID-19,” he said.

“There are other mitigating factors as restaurants, pubs and cafes are closed and people are not eating out so there is reduced exposure to foodborne hazards. People are not reporting to their GP or doctors’ surgeries and they are staying away from A&E in hospitals for fear of becoming infected with SARS-CoV-2. Let’s hope one of the positive outcomes of the pandemic is people will pay more attention to handwashing and personal hygiene.

“The FAO and WHO report highlights the problems food safety authorities are going to face with respect to routine enforcement issues. The real challenge for them is not to take the eye off the ball of what are the real priorities. When it comes to foodborne illness, the food safety authorities need to focus on outbreaks or complaints and identify clusters of cases.

“If it was serious you would need the food inspectors to go in and investigate whatever the implicated food was, where it came from and traceback all implicated foods that are causing the illness and get those off the market straight away. For those larger outbreaks food safety authorities should maintain capacity to deal with them.”

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